"People are moved to change their perception of the old India," he said. "This is the magic of your fingers at the computers." "Sitting here, with your innovations, you are compelling the world to change. And the people who refuse to change, are soon going to become irrelevant."

"The biggest thing, American citizens feel proud of is the people of Indian origin," Modi said. "I congratulate you for this, I salute you." At one time there were discussions in India that the 'brain drain' has to stop, the prime minister said.

"No one thought the brain drain could also be converted into 'brain gain'. And when the time comes, this will come to the use of 'Maa Bharat'."

Coming to California after 25 years Modi said: "I am experiencing a vibrant image of India in California today. I can see a lot of change."

Modi recalled his first trip to the US last year when he was given a rock star like reception by the Indian diaspora at the Madison Square Garden in New York.

The crowds broke into chants of "Modi, Modi" as the prime minister dressed in white kurta and churidars and a light cream Nehru jacket walked to the stage of San Jose's SAP arena.

Before he started speaking Modi was introduced to several US lawmakers from California, including the lone Indian American Congressman Ami Bera, whose parents hail from Gujarat and Democratic Minority leader and former House speaker Nancy Pelosi.

At the outset Modi paid tributes to Indian freedom revolutionary Shaheed Bhagat Singh on his birth anniversary and exhorted the crowd to respond to his call of "Vir Bhagat Singh" with "Amar Rahe Amar Rahe".

More than 45,000 people had registered for free passes for the event organised by an Indian American group at the 18,000-seat SAP Centre.

The rest watched the event on massive television screens that were put up outside.

As at the Madison Square Garden, Modi addressed the people from a rotating stage at SAP Centre with comedian Rajiv Satyal and actress Ashvini Bhave hosting the event.